Merge proc_macro_span_shrink and proc_macro_span

Author: jhpratt

library/proc_macro/src/lib.rs

@@ -494,13 +494,13 @@ impl Span {
     }
 
     /// Creates an empty span pointing to directly before this span.
-    #[unstable(feature = "proc_macro_span_shrink", issue = "87552")]
+    #[unstable(feature = "proc_macro_span", issue = "54725")]
     pub fn start(&self) -> Span {
         Span(self.0.start())
     }
 
     /// Creates an empty span pointing to directly after this span.
-    #[unstable(feature = "proc_macro_span_shrink", issue = "87552")]
+    #[unstable(feature = "proc_macro_span", issue = "54725")]
     pub fn end(&self) -> Span {
         Span(self.0.end())
     }

tests/ui/proc-macro/auxiliary/macro-only-syntax.rs

@@ -10,7 +10,7 @@
 // lossy string reparse hack (https://github.com/rust-lang/rust/issues/43081).
 
 #![crate_type = "proc-macro"]
-#![feature(proc_macro_span, proc_macro_span_shrink)]
+#![feature(proc_macro_span)]
 
 extern crate proc_macro;
 use proc_macro::{token_stream, Delimiter, TokenStream, TokenTree};